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1.
Phys Chem Chem Phys ; 23(39): 22760-22767, 2021 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-34608903

RESUMO

Optimizing the efficiency of heat dissipation across an interface is a great challenge with the continuously increasing integration of microelectronic devices. In this work, an effective method in tuning the heat conduction across the Al/graphene/SiO2 interface is reported. It was found that the interfacial thermal conductance of Al/irradiated graphene/SiO2 can be increased by a factor of 3, as compared with that of Al/pristine graphene/SiO2. The X-ray photoelectron spectroscopy (XPS) analysis indicates that ion irradiation may promote the formation of CO bonds on the irradiated graphene surface, which is beneficial to the enhancement of interfacial thermal conductance. The density functional theory (DFT) calculations reveal that in addition to the formed bonds between O atoms and Al atoms, the adsorption strength between Al and irradiated graphene is intensified, which plays a dominant role in enhancing the interfacial thermal conductance of Al/graphene/SiO2.

2.
Nat Sci Sleep ; 13: 1807-1822, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34675728

RESUMO

Study Objectives: To evaluate the efficacy and safety of acupuncture at HT 7 (Shenmen) and KI 7 (Fuliu) on sleep and comorbid symptoms for chronic insomnia. Methods and Design: A randomized, single-blind, parallel and sham-controlled trial consisted of an acupuncture group (n = 41) and a sham acupuncture group (n = 41). Setting: a tertiary hospital of integrated Chinese and Western medicine. Participants: 82 subjects with chronic insomnia based on the International Classification of Sleep Disorders, Third Edition (ICSD-3). Interventions: a 10-session acupuncture treatment at bilateral HT 7 and KI 7 or sham acupoints with shallow needling was performed over 3 weeks. Measurements: the Pittsburgh sleep quality index (PSQI) and insomnia severity index (ISI) were evaluated at baseline, posttreatment, and at two follow-ups as the primary outcome measures. Polysomnography (PSG) on two consecutive nights, the Beck anxiety inventory (BAI), the Beck depression inventory (BDI) fatigue severity scale (FSS) and the Epworth sleepiness scale (ESS) were evaluated at baseline and posttreatment as the secondary outcome measures. Results: After the treatments, PSQI scores decreased by 5.04 in the acupuncture group and 2.92 in the sham acupuncture group. ISI scores decreased by 7.65 in the acupuncture group and 5.05 in the sham acupuncture group. The between-group differences in the primary outcome measures posttreatment were statistically significant. However, no differences were found between the two groups during the two follow-ups. Regarding the PSG data, there were significantly lower levels of sleep onset latency (SOL), a lower percentage of sleep stage N1 and a higher percentage of sleep stage N3 in the acupuncture group than in the sham acupuncture group. After treatment, there were lower levels of comorbid symptoms (BAI, BDI, FSS and ESS) in both groups. However, no significant differences were observed between the groups. Conclusion: Acupuncture at HT 7 and KI 7 is an effective and safe nonpharmacologic intervention option for chronic insomnia. Clinical Trial Registration: The study was registered at the Chinese Clinical Trial Registry, registration ID: ChiCTR1900023787, China.

3.
Phys Chem Chem Phys ; 2021 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-34515261

RESUMO

Graphene, due to its atomic layer structure, has the highest room temperature thermal conductivity k for all known materials. Thus, it is expected that graphene based materials are the best candidates for thermal management in next generation electronic devices. In this perspective, we first review the in-plane k of monolayer graphene and multilayer graphene obtained using experimental measurements, theoretical calculations and molecular dynamics (MD) simulations. Considering the importance of four-phonon scattering in graphene, we also compare the effects of three-phonon and four-phonon scattering on phonon transport in graphene. Then, we review phonon transport along the cross-plane direction of multilayer graphene and highlight that the cross-plane phonon mean free path is several hundreds of nanometers instead of a few nanometers as predicted using classical kinetic theory. Recently, hydrodynamic phonon transport has been observed experimentally in graphitic materials. The criteria for distinguishing the hydrodynamic from ballistic and diffusive regimes are discussed, from which we conclude that graphene based materials with a high Debye temperature and high anharmonicity (due to ZA modes) are excellent candidates to observe the hydrodynamic phonon transport. In the fourth part, we review how to actively control phonon transport in graphene. Graphene and graphite are often adopted as additives in thermal management materials such as polymer nanocomposites and thermal interface materials due to their high k. However, the enhancement of the composite's k is not so high as expected because of the large thermal resistance between graphene sheets as well as between the graphene sheet and matrix. In the fifth part, we discuss the interfacial thermal resistance and analyze its effect on the thermal conductivity of graphene based materials. In the sixth part, we give a brief introduction to the applications of graphene based materials in thermal management. Finally, we conclude our review with some perspectives for future research.

4.
Langmuir ; 37(35): 10521-10528, 2021 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-34347494

RESUMO

Surface charges inside a nanopore determine the zeta potential and ion distributions and play a significant role in affecting ion transport and the sensitivity of detecting biomolecules. It is of great importance to study the fluctuation of surface charges with the salt concentration and pH in various applications of nanopores. Herein, we proposed a theoretical model to predict the surface charge density of a Si3N4 nanopore, in which both silanol and amine groups were taken into account. It was demonstrated that the surface charge density in the Si3N4 nanopore changes not only with pH but also with the salt concentration. The theoretical model could well predict the experimental results with different salt concentrations, pH values, and pore sizes. The effect of surface functional groups on the isopotential point (pHiep) of the Si3N4 nanopore was also systematically studied. The results indicated that the silanol groups are major determinants of the surface charge, but the influences of the amine groups should not be ignored because the small number of amine groups can change pHiep dramatically. The pHiep value of the Si3N4 nanopore was measured as 4.1, and the ratio of amine over silanol was ascertained as 0.013.


Assuntos
Nanoporos , Transporte de Íons , Modelos Teóricos , Compostos de Silício
5.
Front Immunol ; 12: 665002, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34367132

RESUMO

Immune checkpoint inhibitors (ICIs) have made breakthrough progress in the treatment of various malignant tumors. However, only some patients receiving ICIs obtain long-lasting clinical effects, and some patients still do not achieve remission. Improving the treatment benefits of this part of the population has become a concern of clinicians. IL-1 signaling plays an important role in the tumor microenvironment (TME). However, the relationship between the IL-1 signaling mutation status and the prognosis of colon adenocarcinoma (COAD) patients receiving ICIs has not been reported. We downloaded the data of a COAD cohort receiving ICIs, including prognostic data and mutation data. Additionally, we downloaded the data of a COAD cohort from The Cancer Genome Atlas (TCGA) database, including clinical data, expression data and mutation data. Gene set enrichment analysis (GSEA) was used to assess differences in the activity of some key physiological pathways between the IL-1 signaling mutated-type (IL-1-MT) and IL-1 signaling wild-type (IL-1-WT) groups. The CIBERSORT algorithm was used to evaluate the contents of immune cells in the TME of COAD patients. The multivariate Cox regression model results suggested that IL-1-MT can be used as an independent predictor of a better prognosis in COAD patients receiving ICIs (P = 0.03, HR = 0.269, 95% CI: 0.082-0.883). Additionally, IL-1-MT COAD patients had significantly longer overall survival (OS) (log-rank P = 0.015). CIBERSORT analysis showed that the IL-1-MT group had high infiltration levels of activated dendritic cells (DCs), M1 macrophages, neutrophils, activated natural killer (NK) cells, activated CD4+ memory T cells and CD8+ T cells. Similarly, the IL-1-MT group had significantly upregulated immunogenicity, including in terms of the tumor mutation burden (TMB), neoantigen load (NAL) and number of mutations in DNA damage repair (DDR) signaling. GSEA showed that the IL-1-MT group was highly enriched in the immune response and proinflammatory mediators. Additionally, the expression levels of immune-related genes, immune checkpoint molecules and immune-related signatures were significantly higher in the IL-1-MT group than in the IL-1-WT group. IL-1-MT may be an independent predictor of a good prognosis in COAD patients receiving ICIs, with significantly longer OS in IL-1-MT COAD patients. Additionally, IL-1-MT was associated with significantly increased immunogenicity, activated immune cell and inflammatory mediator levels and immune response-related scores.

6.
Front Immunol ; 12: 676922, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34335575

RESUMO

Immune checkpoint inhibitors(ICIs) that activate tumor-specific immune responses bring new hope for the treatment of hepatocellular carcinoma(HCC). However, there are still some problems, such as uncertain curative effects and low objective response rates, which limit the curative effect of immunotherapy. Therefore, it is an urgent problem to guide the use of ICIs in HCC based on molecular typing. We downloaded the The Cancer Genome Atlas-Liver hepatocellular carcinoma(TCGA-LIHC) and Mongolian-LIHC cohort. Unsupervised clustering was applied to the highly variable data regarding expression of DNA damage repair(DDR). The CIBERSORT was used to evaluate the proportions of immune cells. The connectivity map(CMap) and pRRophetic algorithms were used to predict the drug sensitivity. There were significant differences in DDR molecular subclasses in HCC(DDR1 and DDR2), and DDR1 patients had low expression of DDR-related genes, while DDR2 patients had high expression of DDR-related genes. Of the patients who received traditional treatment, DDR2 patients had significantly worse overall survival(OS) than DDR1 patients. In contrast, of the patients who received ICIs, DDR2 patients had significantly prolonged OS compared with DDR1 patients. Of the patients who received traditional treatment, patients with high DDR scores had worse OS than those with low DDR scores. However, the survival of patients with high DDR scores after receiving ICIs was significantly higher than that of patients with low DDR scores. The DDR scores of patients in the DDR2 group were significantly higher than those of patients in the DDR1 group. The tumor microenvironment(TME) of DDR2 patients was highly infiltrated by activated immune cells, immune checkpoint molecules and proinflammatory molecules and antigen presentation-related molecules. In this study, HCC patients were divided into the DDR1 and DDR2 group. Moreover, DDR status may serve as a potential biomarker to predict opposite clinical prognosis immunotherapy and non-immunotherapy in HCC.

7.
J Dermatolog Treat ; : 1-9, 2021 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-34429003

RESUMO

OBJECTIVE: The current study aimed to investigate the prognosis and treatment of primary cutaneous angiosarcoma (PCA) and primary subcutaneous angiosarcoma (PSCA), and tried to develop a prognostic nomogram model of them. METHODS: A total of 1763 cases retrieved from the Surveillance, Epidemiology, and End Results (SEER) database were retrospectively analyzed. Survival analyses were performed to explore the prognosis of patients and the effects of different treatment methods. All data were randomly allocated into a training set and a testing set to develop and validate the nomogram model. RESULTS: The findings showed that age, sex, grade, tumor size, multiple primary malignant tumors, stage, primary site surgery (PSS), radiotherapy (RT), and chemotherapy (CT) were correlated with prognosis (p < .05). The nomogram achieved good accuracy in predicting the prognosis. PSS + RT + CT showed the best prognosis for patients in stages I, II, and III (p < .05). CONCLUSION: PCA and PSCA are rare with poor prognoses. Patients undergoing PSS may not gain survival benefits from combining with RT or (and) CT, whereas PSS + RT + CT should be actively performed in earlier stages to improve the prognosis of patients. The nomogram model can be used to predict the overall survival rate and guide better treatment.

8.
Artigo em Inglês | MEDLINE | ID: mdl-34306138

RESUMO

Background: Insomnia is often related to stressful events. The hypothalamus-pituitary-adrenal (HPA) axis is related to stress, and dopamine (DA) and DA receptors are involved in the regulation of HPA axis. Electroacupuncture (EA) can improve sleep in individuals with insomnia, but the mechanism is unclear. We demonstrated that EA can improve sleep in rats after cage change through DA and the DA receptors in the HPA axis. Methods: A rat model of insomnia was established by cage change to a dirty cage. The rats in treatment groups were intervened by EA and D1R (or D2R) antagonists. Electroencephalography (EEG) and electromyogram (EMG) were recorded to compare the changes in sleep. The DA, corticotropin-releasing hormone (CRH), adrenocorticotropic hormone (ACTH), and cortisol (CORT) levels in the plasma and hypothalamus were measured by ELISAs, and the D1R and D2R levels were measured by RT-PCR and immunohistochemistry. Results: The dirty group showed a significant increase in the amount of wakefulness and decrease in the amount of NREM sleep, with decreased numbers of long NREM sleep bouts and REM sleep bouts and increased mean duration of wakefulness during the light period. EA and D1R (or D2R) antagonists intervention could improve sleep disturbance by decreasing wakefulness in the light period after cage change, EA and D1R (or D2R) antagonists could increase the hypothalamus DA, CRH, ACTH, CORT level, and the D1R and D2R mRNA levels in the HPA axis, and the effect of EA plus D1R (or D2R) antagonist was not superior to that of EA or D1R (or D2R) antagonists alone. Conclusions: EA can improve the sleep of rats after cage change, and the mechanism may be related to the regulation of DA and D1R or D2R in the HPA axis.

9.
J Phys Chem Lett ; 12(28): 6469-6477, 2021 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-34240883

RESUMO

Many biological assays require effectively and sensitively sorting DNA fragments. Here, we demonstrate a solid-state nanopore platform for label-free detection and separation of short single-stranded DNA (ssDNA) fragments (<100 nt), based on their length-dependent translocation behaviors. Our experimental data show that each sized pore has a passable length threshold. The negative charged ssDNA fragments with length smaller than the threshold can be electrically facilitated driven through the correspondingly sized nanopore along the direction of electric field. In addition, the passable length threshold increases with the pore size enlarging. As a result, this phenomenon is able to be applicable for the controllable selectivity of ssDNA by tuning nanopore size, and the selectivity limitation is up to 30nt. Numerical simulation results indicate the translocation direction of ssDNA is governed by the competition of electroosmosis and electrophoresis effects on the ssDNA and offer the relationship between passable length threshold and pore size.


Assuntos
DNA de Cadeia Simples/análise , DNA de Cadeia Simples/isolamento & purificação , Nanoporos , Nanotecnologia/métodos , Eletroforese , Limite de Detecção , Osmose
10.
Nat Protoc ; 16(7): 3672-3694, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34108731

RESUMO

More than 90% of the human genome is transcribed into noncoding RNAs, but their functional characterization has lagged behind. A major bottleneck in the understanding of their functions and mechanisms has been a dearth of systematic methods for identifying interacting protein partners. There now exist several methods, including identification of direct RNA interacting proteins (iDRiP), chromatin isolation by RNA purification (ChIRP), and RNA antisense purification, each previously applied towards identifying a proteome for the prototype noncoding RNA, Xist. iDRiP has recently been modified to successfully identify proteomes for two additional noncoding RNAs of interest, TERRA and U1 RNA. Here we describe the modified protocol in detail, highlighting technical differences that facilitate capture of various noncoding RNAs. The protocol can be applied to short and long RNAs in both cultured cells and tissues, and requires ~1 week from start to finish. Here we also perform a comparative analysis between iDRiP and ChIRP. We obtain partially overlapping profiles, but find that iDRiP yields a greater number of specific proteins and fewer mitochondrial contaminants. With an increasing number of essential long noncoding RNAs being described, robust RNA-centric protein capture methods are critical for the probing of noncoding RNA function and mechanism.


Assuntos
Proteômica/métodos , RNA não Traduzido/metabolismo , Proteínas de Ligação a RNA/metabolismo , Animais , Linhagem Celular , Núcleo Celular/metabolismo , Cromatina/metabolismo , Reagentes para Ligações Cruzadas/química , DNA Complementar/genética , Camundongos , Ligação Proteica , Proteoma/metabolismo , Reprodutibilidade dos Testes , Raios Ultravioleta
11.
Int J Biol Macromol ; 185: 287-296, 2021 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-34153359

RESUMO

Cellulose microcrystalline (MCC) was widely used in pharmaceutical and chemical industries because of its low degree of polymerization and large specific surface area. As its modified form, dialdehyde cellulose (DAC) was used for cross-linking and immobilizing Rhizopus lipase together with magnetic nanoparticles (MNPs) due to its active aldehyde groups. In this study, in order to maintain the original enzyme activity as much as possible and improve the stability of lipase, the Rhizopus lipase was successfully immobilized on the magnetic dialdehyde cellulose nanoparticles (MDC). Specifically, the immobilization conditions including dosage of DAC, concentration of enzyme, immobilization time and temperature together with pH value of the reaction medium were optimized. Maximum immobilization yield (60.03 ± 0.49%) and recovery activity (88.88 ± 0.61%) can be obtained under the optimal process conditions. The changes in secondary structures of immobilized enzyme revealed the increment in conformational rigidity, which can be reflected in temperature and pH stability as well as tolerance of organic reagents. Additionally, the recovery activity of immobilized enzyme still reached 50.60 ± 0.59% after 30 d of storage and 52.10 ± 0.57% retained after 6 cycles. These results indicated the ideal application prospect of MDC in immobilized enzymes.


Assuntos
Celulose/análogos & derivados , Lipase/química , Nanopartículas de Magnetita/química , Rhizopus/enzimologia , Celulose/química , Estabilidade Enzimática , Enzimas Imobilizadas/química , Proteínas Fúngicas/química , Concentração de Íons de Hidrogênio , Estrutura Secundária de Proteína , Temperatura , Tempo
12.
Nano Lett ; 21(11): 4615-4621, 2021 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-34018741

RESUMO

Friction represents a major energy dissipation mode, yet the atomistic mechanism of how friction converts mechanical motion into heat remains elusive. It has been suggested that excess phonons are mainly excited at the washboard frequency, the fundamental frequency at which relative motion excites the interface atoms, and the subsequent thermalization of these nonequilibrium phonons completes the energy dissipation process. Through combined atomic force microscopy measurements and atomistic modeling, here we show that the nonlinear interactions between a sliding tip and the substrate can generate excess phonons at not only the washboard frequency but also its harmonics. These nonequilibrium phonons can induce resonant vibration of the tip and lead to multiple peaks in the friction force as the tip sliding velocity ramps up. These observations disclose previously unrecognized energy dissipation channels associated with tip vibration and provide insights into engineering friction force through adjusting the resonant frequency of the tip-substrate system.

13.
Emerg Microbes Infect ; 10(1): 1097-1111, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33944697

RESUMO

Monoclonal antibodies (mAbs) encoded by IGHV3-53 (VH3-53) targeting the spike receptor-binding domain (RBD) have been isolated from different COVID-19 patients. However, the existence and prevalence of shared VH3-53-encoded antibodies in the antibody repertoires is not clear. Using antibody repertoire sequencing, we found that the usage of VH3-53 increased after SARS-CoV-2 infection. A highly shared VH3-53-J6 clonotype was identified in 9 out of 13 COVID-19 patients. This clonotype was derived from convergent gene rearrangements with few somatic hypermutations and was evolutionary conserved. We synthesized 34 repertoire-deduced novel VH3-53-J6 heavy chains and paired with a common IGKV1-9 light chain to produce recombinant mAbs. Most of these recombinant mAbs (23/34) possess RBD binding and virus-neutralizing activities, and recognize ACE2 binding site via the same molecular interface. Our computational analysis, validated by laboratory experiments, revealed that VH3-53 antibodies targeting RBD are commonly present in COVID-19 patients' antibody repertoires, indicating many people have germline-like precursor sequences to rapidly generate SARS-CoV-2 neutralizing antibodies. Moreover, antigen-specific mAbs can be digitally obtained through antibody repertoire sequencing and computational analysis.


Assuntos
Anticorpos Monoclonais/sangue , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , COVID-19/imunologia , SARS-CoV-2/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Monoclonais/imunologia , Sequência de Bases , COVID-19/sangue , Estudos de Casos e Controles , Epitopos de Linfócito B , Feminino , Células HEK293 , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Moleculares , Filogenia , Conformação Proteica , Receptores de Antígenos de Linfócitos B/genética
14.
Mol Ther Nucleic Acids ; 24: 449-461, 2021 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-33868788

RESUMO

Liver cancer presents a challenge in today's healthcare system. This study aimed at investigating the effects of Fer-1 like family member 4 (FER1L4) on chemotherapy resistance and liver cancer development by using clinically collected liver cancer tissues and commercially purchased human liver cancer cisplatin-resistant cell line HUH-7/DDP. Bioinformatics analysis, dual luciferase reporter gene assay, and RNA pull-down were applied to predict and verify the possible binding relationships. The expressions of FER1L4, E2F transcription factor 1 (E2F1), microRNA-106a-5p (miR-106a-5p), or miR-372-5p were altered in the cells, followed by flow cytometry, Cell Counting Kit-8 (CCK-8), and Transwell assays to evaluate apoptotic, proliferative, and invasive abilities in vitro and nude mice xenografts to observe tumor growth in vivo. FER1L4 was highly expressed and miR-106-5p and miR-372-5p were poorly expressed in tumor cells and tissues. FER1L4 knockdown or the overexpression of miR-106-5p and miR-372-5p inhibited the cancerous cell proliferation and invasion while promoting apoptosis. FERIL4 silencing increased the miR-106-5p/miR-372-5p expression to inhibit the E2F1-activated nuclear factor κB (NF-κB) pathway. Besides, overexpressing FER1L4 led to an increased tumor growth in nude mice, which was reversed by the NF-κB inhibitor pyrollidine dithiocarbamate (PDTC). In conclusion, the results indicated that FER1L4 could inhibit the expression of miR-106a-5p/miR-372-5p, to activate E2F1-mediated NF-κB pathway, leading to drug resistance in liver cancer.

15.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 29(2): 574-580, 2021 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-33812433

RESUMO

OBJECTIVE: To investigate the factors affecting the chronicity of childhood primary immune thrombo-cytopenia (ITP) and compare the efficiency of different first-line treatment regimens. METHODS: Children with ITP hospitalized in our hospital from September 2013 to October 2018 were retrospectively analyzed. RESULTS: Three hundred and one children (150 males and 151 females) were included in this study, with a median age of 8 (0.17-17) years old, and 110 (36.5%), 92 (30.6%), and 99 (32.9%) cases were grouped into newly diagnosed, persistent, and chronic ITP, respectively. The median of follow-up was 41.92 (1.07-74.03) months. At the end of the follow-up (October 2019), among the 202 newly diagnosed/persistent ITP children, 79 cases (59 newly diagnosed and 20 persistent ITP) achieved remission within 1 year after initial diagnosis, with a remission rate of 39.3%; 122 cases (50 newly diagnosed and 72 persistent ITP) developed chronic disease, with a chronicity rate of 60.7%; one case underwent splenectomy. In 99 cases with chronic ITP, 5 cases underwent splenectomy. Multivariable logistic regression analysis showed that, the insidious onset of symptoms (OR=3.754, 95%CI: 1.882-7.488, P=0.000) increased the risk of chronicity, while the positive antibody to anti-platelet membrane glycoprotein (OR=0.446, 95%CI: 0.224-0.888, P=0.021) might reduce the risk of chronicity. And no difference was found by the analysis of subtype of anti-platelet membrane glycoprotein (P=0.305). The efficacy of the first-line treatment of intravenous immunoglobulin (IVIG) alone or combined with steroid was better than that of steroid alone (P=0.028, 0.028), however, the efficiency was not significantly different between IVIG alone and combined with steroid (P=0.086). CONCLUSION: Insidious onset of symptoms in pediatric ITP increases the risk of chronicity, while the positive titer of anti-platelet membrane glycoprotein may reduce the risk. In the first-line treatment for the newly diagnosed/persistent children. The efficacy of IVIG alone or combined with steroid is better than that of steroid alone.


Assuntos
Púrpura Trombocitopênica Idiopática , Adolescente , Criança , Criança Hospitalizada , Feminino , Humanos , Imunoglobulinas Intravenosas , Masculino , Estudos Retrospectivos , Esplenectomia
16.
Nat Nanotechnol ; 16(7): 764-768, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33859389

RESUMO

Fascinating phenomena can occur as charge and/or energy carriers are confined in one dimension1-4. One such example is the divergent thermal conductivity (κ) of one-dimensional lattices, even in the presence of anharmonic interatomic interactions-a direct consequence of the Fermi-Pasta-Ulam-Tsingou paradox proposed in 19555. This length dependence of κ, also known as superdiffusive phonon transport, presents a classical anomaly of continued interest6-9. So far the concept has remained purely theoretical, because isolated single atomic chains of sufficient length have been experimentally unattainable. Here we report on the observation of a length-dependent κ extending over 42.5 µm at room temperature for ultrathin van der Waals crystal NbSe3 nanowires. We found that κ follows a 1/3 power law with wire length, which provides experimental evidence pointing towards superdiffusive phonon transport. Contrary to the classical size effect due to phonon-boundary scattering, the observed κ shows a 25-fold enhancement as the characteristic size of the nanowires decreases from 26 to 6.8 nm while displaying a normal-superdiffusive transition. Our analysis indicates that these intriguing observations stem from the transport of one-dimensional phonons excited as a result of elastic stiffening with a fivefold enhancement of Young's modulus. The persistent divergent trend of the observed thermal conductivity with sample length reveals a real possibility of creating novel van der Waals crystal-based thermal superconductors with κ values higher than those of any known materials.

17.
Am J Physiol Regul Integr Comp Physiol ; 320(6): R835-R850, 2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-33826428

RESUMO

Pulmonary hypertension (PH) is a serious disease with pulmonary arterial fibrotic remodeling and limited responsiveness to vasodilators. Our data suggest that mild acidosis induced by carbonic anhydrase inhibition could ameliorate PH, but the vascular mechanisms are unclear. We tested the hypothesis that carbonic anhydrase inhibition ameliorates PH by improving pulmonary vascular reactivity and relaxation mechanisms. Male Sprague-Dawley rats were either control normoxic (Nx), or injected with Sugen 5416 (20 mg/kg, sc) and subjected to hypoxia (9% O2) (Su + Hx), or Su + Hx treated with acetazolamide (ACTZ, 100 mg/kg/day, in drinking water). After measuring the hemodynamics, right ventricular hypertrophy was assessed by Fulton's Index; vascular function was measured in pulmonary artery, aorta, and mesenteric arteries; and pulmonary arteriolar remodeling was assessed in lung sections. Right ventricular systolic pressure and Fulton's Index were increased in Su + Hx and reduced in Su + Hx + ACTZ rats. Pulmonary artery contraction to KCl and phenylephrine were reduced in Su + Hx and improved in Su + Hx + ACTZ. Acetylcholine (ACh)-induced relaxation and nitrate/nitrite production were reduced in pulmonary artery of Su + Hx and improved in Su + Hx + ACTZ. ACh relaxation was blocked by nitric oxide (NO) synthase and guanylate cyclase inhibitors, supporting a role of NO-cGMP. Sodium nitroprusside (SNP)-induced relaxation was reduced in pulmonary artery of Su + Hx, and ACTZ enhanced relaxation to SNP. Contraction/relaxation were not different in aorta or mesenteric arteries of all groups. Pulmonary arterioles showed wall thickening in Su + Hx that was ameliorated in Su + Hx + ACTZ. Thus, amelioration of pulmonary hemodynamics during carbonic anhydrase inhibition involves improved pulmonary artery reactivity and NO-mediated relaxation and may enhance responsiveness to vasodilator therapies in PH.


Assuntos
Inibidores da Anidrase Carbônica/farmacologia , Hipertensão Pulmonar/fisiopatologia , Músculo Liso Vascular/fisiopatologia , Artéria Pulmonar/fisiopatologia , Animais , Hipóxia/fisiopatologia , Masculino , Artérias Mesentéricas/fisiopatologia , Óxido Nítrico/metabolismo , Óxido Nítrico/farmacologia , Ratos Sprague-Dawley , Vasodilatação/efeitos dos fármacos
18.
Cell Death Differ ; 28(1): 139-155, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32678307

RESUMO

Ovarian cancer is the most lethal malignant tumor of female reproductive system. It is well-known that induction of STING-mediated type I interferons can enhance the resultant antitumor activity. However, STING pathway is usually inactivated in cancer cells at multiple levels. Here, we identified deubiquitinase USP35 is upregulated in ovarian cancer tissues. High level of USP35 was correlated with diminished CD8+ T cell infiltration and poor prognosis in ovarian cancer patients. Mechanistically, we found that silencing USP35 reinforces the activation of STING-TBK1-IRF3 pathway and promotes the expression of type I interferons. Our data further showed that USP35 can directly deubiquitinate and inactivate STING. Interestingly, activation of STING promotes its binding to USP35 in a STING phosphorylation-dependent manner. Functionally, we found that knockdown of USP35 sensitizes ovarian cancer cells to the DNA-damage chemotherapeutic drug cisplatin. Overall, our study indicates that upregulation of USP35 may be a mechanism of the restricted STING activity in cancer cells, and highlights the significance of USP35 as a potential therapeutic target for ovarian cancer.

19.
Environ Sci Pollut Res Int ; 28(2): 1697-1711, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32856243

RESUMO

Since the power unbundling reform in 2002, China's power industry has been a typical sector moving towards marketization. The supply-side structural reform that began in 2015 has intensified the competition among China's power generation enterprises. In this context, this paper combines a data envelopment analysis (DEA) game cross-efficiency model with the Malmquist index approach to investigate the dynamic environmental efficiency of China's power generation enterprises in a competitive market. Furthermore, the system generalized method of moments (SYS-GMM) is employed to analyze the influences of factors on the dynamic environmental efficiency. The results show that: (1) Compared with the basic DEA Charnes-Cooper-Rhodes (CCR)-Malmquist index model, the DEA game cross-Malmquist index approach can enhance the discrimination among the decision making units (DMUs). (2) The change in the overall dynamic environmental efficiency of China's power generation enterprises mainly comes from the catch-up effect, while technological progress has not played a role as significant as expected. (3) The installed capacity growth rate, implementation of carbon emission trading pilots, economic growth rate, and enterprise ownership all affect the dynamic environmental performance of China's power generation enterprises during the study period.


Assuntos
Eficiência , Indústrias , China , Desenvolvimento Econômico , Características da Família
20.
ACS Nano ; 14(11): 15349-15360, 2020 11 24.
Artigo em Inglês | MEDLINE | ID: mdl-33151055

RESUMO

Molecular machines hold keys to performing intrinsic functions in living cells so that the organisms can work properly, and unveiling the mechanism of functional molecule machines as well as elucidating the dynamic process of interaction with their surrounding environment is an attractive pharmaceutical target for human health. Due to the limitations of searching and exploring all possible motors in human bodies, designing and constructing functional nanorobots is vital for meeting the fast-rising demand of revealing life science and related diagnostics. Here, we theoretically designed a nanoparticle-DNA assembled nanorobot that can move along a solid-state membrane surface. The nanorobot is composed of a nanoparticle and four single-stranded DNAs. Our molecular dynamics simulations show that electroosmosis could be the main power driving the movement of a nanorobot. After the DNA strands were one-to-one captured by the nanopores in the membrane, by tuning the surface charge density of each nanopore, we have theoretically shown that the electroosmosis coupled with electrophoresis can be used to drive the movement of the nanorobot in desired directions along the graphene membrane surface. It is believed that the well-controlled nanorobot will lead to many exciting applications, such as cargo delivery, nanomanipulation, and so on, if it is implemented in the near future.


Assuntos
Nanopartículas , Nanoporos , DNA , Eletro-Osmose , Eletroforese , Humanos
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